Seeing smoke rising can be unnerving, even when it is a fire started on purpose to help our forest. This is known as a prescribed burn. So why do they do it? Arizona Department of Environmental Quality (ADEQ) has the answers.
In Central and Northern Arizona, we love our forests. Our forests are the setting for various recreational activities and provide the backdrop for our community. But, while it may not always be evident, our forests are sick. Many parts of our forest are susceptible to insect infestations, disease, and catastrophic wildfire.
1. It is because of our love of our forest, and our desire to improve its health that we prescribe fire. Much like a doctor prescribes medication to a sick patient, Forest Service managers sometimes prescribe fire to improve the health of our local forests.
Prescribed burns are termed such because they are conducted within a “prescription” that defines the fuel moisture levels, air temperatures, wind conditions, and relative humidity levels that are appropriate for each project.
All prescribed fire activity is dependent on personnel availability, fuel conditions, weather – including ventilation conditions, and approval from the Arizona Department of Environmental Quality (ADEQ).
Fire managers strive to minimize smoke impacts to the community by working closely with ADEQ and neighboring forests to monitor air quality. Tactics to keep smoke impacts as minimal as possible include canceling approved burns when conditions aren’t favorable, finding alternative uses for the debris in slash piles, timing daytime ignitions to allow the majority of smoke time to disperse prior to settling overnight, and burning larger sections at a time to ultimately limit the number of days smoke is in the air.
2. When it comes to prescribed burns, it’s not just the environment that reaps benefits, but communities too. Many folks like to be near nature. Unfortunately, this translates to quite a few Arizona homes butting up against fuels ready to feed a fire. The term Wildland Urban Interface (WUI) refers to this notion.
3. Another aim of select prescribed burns is protecting these susceptible population centers by creating effective fire breaks in declared WUI zones. If a wildfire were to break out, the lack of burnable material between an advancing fire and residences (i.e., a fire break) would halt, or at least slow, its movement.
Overall, a potential emergency situation becomes more manageable, both for fire officials fighting the wildfire and also by providing more time for affected public to evacuate out of harm’s way, if necessary. Eliminating excessive fuel loading through low intensity prescribed burns are a means to accomplish this goal in a safer manner for firefighter staff.
Although prescribed burn projects could range from only a few acres up to thousands, the ultimate outcome is healthier ecosystems becoming resilient to the feared catastrophic wildfire. The recognition of this makes for numerous governmental agencies who are tied to land management having involvement with prescribed burns in some capacity.
A majority of Arizona’s prescribed burns are conducted by the United States Forest Service, but other agencies partaking in prescribed burn projects have included tribal nations, United States Fish and Wildlife Service, Arizona State Forestry, Arizona Department of Transportation, national parks, state parks, Bureau of Land Management, and even the Department of Defense.
As a word of caution, if you are traveling through an area with planned prescribed burn projects be prepared for sudden roadway visibility restrictions caused by smoke. Even when smoke is not impacting a roadway, there still could be fire personnel and equipment around managing the scene. Using caution by heeding posted traffic signs and reducing speed when appropriate are always encouraged.
If you see smoke and want to check if it's a prescribed burn, go to Arizona Department of Environmental Quality's designated page: http://smoke.azdeq.gov/